HomeMy WebLinkAbout2006-06-05; Traffic Safety Commission; ; Establish a prima facie speed limit upon Camino Junipero from Rancho Santa Fe Road to its terminus at Avenida Amapola(
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF: June 5, 2006 ITEMNO.6A
LOCATION: Camino Junipero, Rancho Santa Fe Road to its terminus at A venida Amapola
INITIATED BY: Deputy City Engineer, Transportation
REQUESTED ACTION: Establish a prima facie speed limit upon Camino Junipero from
Rancho Santa Fe Road to its terminus at A venida Amapola.
BACKGROUND:
Camino Junipero is a four-lane road located in the southeast portion of Carlsbad.
The road terminates immediately east of A venida Amapola (see Exhibit 1). The Carlsbad
Police Department has received complaints of vehicles racing on Camino Junipero,
which does not have a posted speed limit.
SETTING SPEED LIMITS:
Mobility is enhanced and overall traffic flow improved when drivers are operating their
vehicles at a speed that is reasonable and safe. In fact, the premise of CVC section 22350,
Basic Speed Law, is that no person shall drive upon a road at a speed greater than is
reasonable and prudent taking into account weather, visibility, and traffic on the road and
in no event at a speed that endangers the safety of others.
Roads in Carlsbad are designed in accordance with engineering standards to satisfy the
goals of a safe roadway and to enhance efficient traffic flow. One way to achieve the
goals is to establish proper and reasonable speed limits that can be enforced. Speed limits
that are reasonable can help to achieve voluntary compliance by the majority of drivers
without need for the presence of a police officer. Laws and/or the establishment of speed
zones that arbitrarily restrict travel by the majority of motorists can lead to wholesale
violations of the posted speed limit.
In the City of Carlsbad, the most predominant practice for managing speed is by legally
establishing a prima facie speed limit and then posting the speed limit upon the road with
regulatory signs. Police enforcement is used to target the most egregious violators of the
speed limit. A fundamental tenet is that laws are enacted to protect the majority of the
public by regulating the unsafe or unreasonable actions of the few.
The most common method of establishing speed limits incorporates traffic engineering
principles and other factors, such as using the results of a speed survey, into the
Traffic and Engineering Survey. Speed limits are established by ordinance and then
posted on the roadway to indicate the maximum reasonable speed for a driver to operate a
vehicle under ideai conditions in off-peak free flowing conditions. The three most
persuasive arguments to consider when setting a realistic, or rational, speed limit are:
1. Critical speed (85th percentile speed)
2. Collision history
3. Conditions that may not be readily apparent to the driver
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CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF: June 5, 2006
(continued)
ITEMNO. 6A
The premise implied in sfeed zoning is that the majority of drivers are operating their
vehicles at or near the 85t percentile speed. Drivers that operate their vehicle at speeds
higher than the 85 th percentile speed should be the focus of the police. An important speed
zoning concept is that the disparity in speed between vehicles on the road is reduced
when prima facie speed limits are established at or near the 85th percentile speed and, as a
result, safety is enhanced. Also, a speed limit that is established based upon the 85th
percentile speed will increase driver respect for the speed limit sign. Only those signs that
have the respect of the roadway user will have a positive effect to control traffic.
Reviewing the collision history on a roadway is an important element in the process to
establish a speed limit. The review will reveal if there is a high incidence of speed-related
collisions on the road at specific locations. Absent a significant collision history
attributed to speed, it can be concluded that drivers are operating their vehicle in a
reasonable and prudent manner at the speed they chose to drive.
Design factors such as the geometric elements of the road, sight distance, or other factors
may have a significant impact on the free flowing speed chosen by drivers. This driver
chosen speed, in tum, is considered when establishing a prima facie speed limit.
A number of factors may be considered when establishing a prima facie speed limit.
The 2003 MUTCD lists such factors as:
A. Road characteristics, shoulder condition, grade, alignment, and sight distance;
B. The pace speed;
C. Roadside development and activity; and
D. Reported crash experience for at least a 12-month period.
As stated, basic speed law requires drivers to operate their vehicle at a speed that takes
into account all roadway factors, environmental elements, adjacent land uses, and other
traffic on the road. These are, in general, all readily apparent factors. Warning signs
placed on the roadway can alert drivers to the presence of an unseen or unanticipated
condition. As a result, drivers can operate their vehicle in a reasonable and prudent
manner by adjusting speed for the condition that may be encountered.
In summary, through the use of engineering, educational, and enforcement techniques, the
management of vehicle speed is conducted. Voluntary public compliance with the posted
speed limit is the goal when determining a realistic prima facie speed limit to establish.
The realistic speed limit takes into consideration the normally competent and careful
actions of a reasonable driver and provides for the regulation of unreasonable behavior by
a few individuals. A posted speed limit should be readily accepted by drivers, be fair and
reasonable, be related to risk on the roadway, be determined by the majority of drivers,
and one that has a factual foundation.
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF: June 5, 2006
( continued)
DATA:
ITEMNO. 6A
Camino Junipero is classified as a major arterial on the Circulation Plan of the
Circulation Element found in the City of Carlsbad General Plan. However, its
cross-section has been modified from the standard cross-section for a major arterial
roadway to one having a curb-to-curb width of 64 feet (versus the standard 82 feet). The
road has two traffic lanes in each direction extending to the intersection of A venida
Maravilla where the southbound lane is then reduced to one lane, several hundred feet
east of A venida Maravilla. A bicycle lane is striped on each side of the road. Immediately
east of Rancho Santa Fe Road, a raised median has been constructed on Camino Junipero
for a distance of 150 feet where it terminates and a striped double double yellow median
has been installed on the remaining length of Camino Junipero.
A traffic signal controls both sides of Camino Junipero at its intersection with
Rancho Santa Fe Road. Three streets intersect Camino Junipero east of Rancho Santa Fe
Road and all are controlled by a stop sign when entering Camino Junipero. Two of the
intersecting streets, A venida Maravilla and A venida Amapola, are configured as a
T-intersection. The only four-leg intersection southerly of Rancho Santa Fe Road on
Camino Junipero has side streets with two different names. The westerly street is named
Camino Cereza and the easterly street is named Corte Romero.
Camino Junipero terminates immediately east of Avenida Amapola where an M-9
barricade and chainlink fence extends across the roadway. The barricade will be removed
in the future when additional residential development takes place. A trail easement and a
San Diego Gas and Electric easement intersect Camino Junipero. Both easements are
served by concrete driveways have been constructed on Camino Junipero to provide
access. Each driveway is located about 300 feet southerly of Avenida Maravilla.
Centerline roadway grades on Camino Junipero vary from 1.2% to 6.0%.
Concrete sidewalks, curb and gutter, and street lights have been constructed to city
standards on each side of the roadway. Parking is prohibited on both sides of
Camino Junipero due to the presence of the bicycle lanes.
Camino Junipero opened to traffic in early 2005 and there have been no reported traffic
collisions on this roadway.
On May 9, 2006, a traffic count was obtained on Camino Junipero to measure the
two-way, 24-hour average daily traffic volume. The recent count data is indicated on
Table A.
TABLE A
24-HOUR TRAFFIC VOLUMES
CAMINO JUNIPERO
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF: June 5, 2006 ITEMNO. 6A
( continued)
Staff conducted a speed survey on Camino Junipero on May 9, 2006 to obtain data to
calculate the critical speed of vehicles. The critical speed, commonly called the
85th percentile speed, is the free flowing speed at which 85 percent of the vehicles are
traveling at or below. A sample of 100 vehicles was measured to determine the critical
speed. The critical speed is an important factor required to be considered in the evaluation
of the appropriate prima facie speed to post upon a roadway.
The 85th percentile speed has been determined throughout the United States to generally
conform to a safe and reasonable speed limit. The 2003 Manual on Uniform Traffic
Control Devices (MUTCD) California Supplement provides guidance when a speed limit
is to be posted. It states that "the speed limit should be established at the nearest 10 km/h
(5 mph) increment to the 85 th percentile speed. However, in matching existing conditions
with the traffic safety needs of the community, engineering judgment may indicate the
need for a further reduction of 10 km/h (5 mph)."
California Vehicle Code section 627 defines the term "Engineering and Traffic Survey"
and lists its requirements, as follows:
627. (a) "Engineering and traffic survey," as used in this code, means a survey of highway
and traffic conditions in accordance with methods determined by the Department of
Transportation for use by state and local authorities.
(b) An engineering and traffic survey shall include, among other requirements
deemed necessary by the department, consideration of all of the following:
(1) Prevailing speeds as determined by traffic engineering measurements.
(2) Accident reports.
(3) Highway, traffic, and roadside conditions not readily apparent to the driver.
(c) When conducting an engineering and traffic survey, local authorities, in
addition to the factors set forth in paragraphs (1) to (3), inclusive, of subdivision (b) may
consider all of the following:
(1) Residential density, if any of the following conditions exist on the particular
portion of highway and the property contiguous thereto, other than a business district;
(A) Upon one side of the highway, within a distance of a quarter of a mile, the
contiguous property fronting thereon is occupied by 13 or more separate dwelling houses
or business structures.
(B) Upon both sides of the highway, collectively, within a distance of a quarter of a
mile, the contiguous property fronting thereon is occupied by 16 or more separate
dwelling houses or business structures.
(C) The portion of highway is longer than one-quarter of a mile but has the ratio of
separate dwelling houses or business structures to the length of the highway described in
either subparagraph (A) or (B).
(2) Pedestrian and bicyclist safety.
( (
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF: June 5, 2006
( continued)
ITEMNO. 6A
Staff completed the Engineering and Traffic Survey (attached) for Camino Junipero
from Rancho Santa Fe Road to its temporary terminus at A venida Amapola. Results of
the speed survey, contained within the Engineering and Traffic Survey that was
conducted on Camino Junipero, are summarized in Table B.
TABLEB
SPEED SURVEY DATA FOR CAMINO JUNIPERO
at Corte Romero/Camino
Cereza
The pace speed is the 10 mile per hour range of speeds that contain the highest number of
observed vehicles. Generally, the critical speed is located in the upper range of the pace
speed.
Sections 22357 and 22358 of the California Vehicle Code authorize local authorities to
establish a prima facie speed limit on the basis of the results of an Engineering and
Traffic Survey. The Engineering and Traffic Survey considers such factors as the number
of collisions that have occurred on the road segment, roadway features, adjacent land
uses, driveway locations, traffic volumes, pedestrian volumes, critical speed, horizontal
and vertical alignment, stopping sight distance, and conditions that may not be readily
apparent to the driver.
RECOMMENDATION:
Based upon the results of the Engineering and Traffic Survey, the Traffic Safety
Coordinating Committee recommends establishing a 45 mile per hour prima facie speed
limit upon Camino Junipero from Rancho Santa Fe Road to its terminus.
NECESSARY CITY COUNCIL ACTION:
An ordinance will be required to be adopted by the City Council to establish the 45 mile
per hour prima facie speed limit upon Camino Junipero, as recommended.
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PROPOSED
SPEED ZONE
NOT TO SCALE
PROJECT NAME
LOCATION MAP
PROPOSED SPEED ZONE
CAMINO JUN/PERO
DRAWN BY: SCOTT £VANS. CARLSBAD £NG/N££R/NG DEPT. 5 17 06 C: TRAmc SP££D ZONES SP££D ZONE-CAMINO JJNIP£RO.DWG
EXHIBIT
1
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CITY OF CARLSBAD
ENGINEERING AND TRAFFIC SURVEY
STREET: Camino Junipero
LIMITS: Rancho Santa Fe Road to Avenida Amapola
A. Prevailing Speed Data:
Date of Speed Survey
Location of Speed Survey
85th Percentile
10 MPH Pace
Percent in Pace
Posted S eed Limit
B. Midblock Accident History:
(1/01/05 to 3/31/06 -road opened
In January 2005)
Speed-Related Accidents
Total Accidents
Accidents/Million Vehicle Miles (MVM)
California Statewide Accidents/MVM
C. Traffic Factors:
Average Daily Traffic
Traffic Controls
Pedestrian/Bicycle Traffic
Bicycle Lanes
On-Street Parkin
D. Roadway Factors:
Street Classification
Length of Segment
Roadway Width
Number of Lanes
Vertical Alignment
Horizontal Alignment
Sidewalks
Driveways
Street Li hlin
0
0
None
Direction: Northbound/Southbound
5/09/06
At Corte Romero/Camino Cereza
43MPH
35 to 45 MPH
79%
No Posted S eed Limit
2.14 (2003 Rate for 4 or More Divided Lanes)
2,022 -East of Rancho Santa Fe Road (5/09/06)
Traffic Signal at Rancho Santa Fe Road
Light
Bicycle Lane on Each Side
Parking Prohibited on Each Side
Major Arterial
0.56Mi.
64 Feet (Curb-to-Curb)
Two Lanes Each Direction -Excepted as Noted Below
Roadway Grades Vary from 1.2% to 6%
Curvilinear
Sidewalk on Each Side
One Utility Easement Driveway and One Trail Easement Driveway
Street Lights on Ec1ch Side
E. Special Conditions: Southbound travel lanes are reduced to one lane south of Avenida Maravilla. A curve warning sign warns
southbound motorists that the must turn ri ht at Avenida Arna ola where the road tern oraril terminates.
G. Remarks/Conditions Not Readily Apparent: Travel lanes are separated by a raised median at Rancho Santa Fe Road and the
remainder of the road by a painted median. The roadway temporarily terminates at Avenida Amapola and will be extended in the
future as develo ment occurs.
H. Traffic Engineer's Recommendation (Explanation): This speed zone satisfies the conditions of Section 627 of the California
Vehicle Code and has been prepared and evaluated in accordance with the Manual on Uniform Traffic Control Devices (MUTCD)
2003 Edition as amended by the MUTCD 2003 California Supplement with respect to design and prevailing speeds, accident
records, pedestrian and bicyclist safety, intersection and driveway spacing, and roadside and traffic conditions not readily
a arent to the driver. As eed limit ostin of 45 MPH is found to be a ro riate and ·ustified.
DATE: 5/09/06 TIME: 1 :45 PM
WEATHER: Overcast and Mild
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CITY OF CARLSBAD
SPEED SURVEY-----------.
TO 3:10 PM TOTAL VEHICLES:
CRITICAL SPEED:
LOCATION: Camino Junipero at Corte. Romero/Camino Cereza VEHICLES IN PACE:
OBSERVER/RECORDER: -J. Gale ---------PACE SPEED(S):
NONE
POSTED SPEED LIMIT
EASTBOUND
DIRECTION OF TRAVEL
MPH # % :E # % %tile % #
65
64
63
62
61
60
59
58
57
56
55
54
53
52"
51
50
49 .
48
47
46 X X
45 X X
44 X X X X
43 X X X X X X X
42 X X X X
41 X
40 X X X X
39 X X
38 X X X X X X X
37 X X
36 X X
35 X X X
34
33 X
32
31
30
29
28
27
26
25
24
23
22
21
2 4 3 3 100 2 1
3 6 5 5. 97 4 2
5 10 6 6 92 2 1
8 16 12 12 86 8 4
5 10 8 8 74 6 3
2 4 3 3 66 2 1
5 10 8 8 63 6 3
3 6 7 7 55 8 4
8 16 10 10 48 4 2
3 6 10 10 38 14 7
2 4 6 6 28 8 4
3 6 9 9 22 12 6
1 1 13 2 1
1 2 6 6 12 10 5
4 4 6 8 4
2
2
1 1 2 2 1
1 1 1 2 1.
Engineering Department
Transportation Division
-----------.. .. -· -··-------
100
43 MPH
79 %
35 TO 45 MPH
WESTBOUND
DIRECTION OF TRAVEL
MPH
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
X 46
X X 45 .. 44
X X X 43
X X 42
41
X X 40
X X X X· 39
X X 38
X X X X X X X 37
X X X 36
X X X X X 35
34
X X X X 33
X X X 32
31
30
X 29
X 28
27
26
25
24
23
22
21